Method of heating



July 7, 1936. c. YA. DUNHAM ET AL. 2,047,015

METHOD OF HEATING y Original Filed Aug. 20. 1931 9 Sheets-Sheet 1 "nu 7l' l 44 l Hl HHH and July 7,1936.

c. A. DUNHAM ET Al.

METHOD OF HEAT ING original Filed Aug. 2o. 1951 9 Sheets--SheerI 2 g TUTIE- [Ia 022 M'Alza @www METHOD OF HEATING 9 Sheets-Sheet 5 Original Firled Aug. 20, 1931 l, l Q i m vwWMM Mi.. ,Q r Q Q im Y m@ 25m. M N |1 l a i m l i l ily um, l 1,1. VJ l\ HP 1.? ,Wm, |`w El;

.uly 7,1936 c. A. DUNHAM ET A1.

METHOD OF HEATING Original Filed Aug. 20. 19E-51 9 Sheets-Sheet i July 7,41936. c. A. DUNHAM E1' AL METHOD OF HEATING Original Filed Aug. 20. 1951 9 Sheets-Sheet 5 July 7, 1936. c. A. DUNHAM E1' AL 2,047,015

METHOD oF HEAMNG Original Fled Aug. 2O. 1951 9 Sheets-Sheet 6 u bv i?? t9/ fig ya J9 J8 L 5;? i113 1 H la J9 f gli j@ `F" i 10,0? l ZZ ZZLIMZ;

July 7, 1936- c. A. DUNHAM Er A1. 2,047,015

METHOD OF HEAT ING Original Filed Aug. 20, 1931 9 Sheets-Sheet 'T July 7, 1936. c. A. DUNHAM ET Al.

METHOD OF HEATING 9 Sheets-Sheet 8 Original Filed Aug. 20, 1951 July 7, 1936.

c. A. DUNHAM ET A1. 2,047,015

METHOD o? HEATING Original Filed Aug. 20. 1931 9 Sheets-Sheet 9 Irufe nO-ns Paten/ted July 7, 1936l UNITED STATES METHOD F HEATING Clayton A. Dunham and `Aubral R. Dunham,

Glencoe, Ill., assignors to Experimental Laboratories Incorporated, Chicago, Ill., a corporation of Illinois Application August 20, 1931, Serial No. 558,293 Renewed June 12, 1935 10 Claims.` (Cl. 237-12) This invention relates to a new and improved method for heating buildings, and more particularly to a heating system of the internal combustion boiler type in which a heating medium consisting of mixed steam and products of combustion is created and transmitted to and through the radiating system.

'Ihe entire heating system is substantially closed from the space within the building, except for the inlet for combustion air, and thesystem is -operated under a reduced pressure produced by a fan or other suction means connected with the outlets of the radiators. This exhausting mechanism draws out from the radiating system and expels to the outer atmosphere the noncondensible gases after they have given up most of their heat in the radiators, and also maintains a reduced pressure in both the radiating system and the generator. Steam condensed in the radiating system is returned by gravity to the generator for re-conversion into steam. The sub-atmospheric pressure maintained in the generator serves to draw in air for combustion purposes, and since the system is operated under reduced pressure, if any leakage occurs, it will be of air into the system rather than the escape of steam or combustion gases therefrom. Control means operable manually from a location inthe building remote from the generator is provided for controlling and adjusting the generator burners, and the exhausting mechanism. Signal devices adjacent the manually operable control means indicate the conditionk at any time of the generator and exhausting apparatus.

Thermostatically operating control means also automatically control the supply of fuel to the burners. A primary pilot flame. vwhich is normally constantly burning, serves to ignite the main burner. Thermostatic means actuated by v this pilot burner serves to hold open a main cutoif valve in the fuel supply` conduit so that if for any reason this primary pilot burner is extinguished, the supply of fuel to all of the burners will be cut off. A secondary pilot or control burner also operates through thermostatic means to control the ilow of fuel to the main burner. The supply of fuel to this secondary pilot is under the controlof thermostatic means subject to the temperature of the heating medium or gases at a point remote from the generator. The intensity of this secondary pilot name is also influenced by the draft of the combustion air caused by the exhausting mechanism, so that the supply of fuel to the main burner will be cut off when, or shortly after, the exhausting mechanism ceases to operate. Certain additional or alternative forms of automatic control mechanism for the burners are disclosed in the specifications which follow.

The present invention relates to certain improvements on and additions to the type of heat- 5 ing system disclosed in our copending applications Serial No. 376,537, led' July 8, 1929, and Serial No. 466,002, led July 7, 1930. Many of the principles of operation and features of construction utilized in the present improved systemv 10 are claimed more broadly in these co-pending applications.

The principal object of this invention is to provide an improved method for heating, of the type briefly described hereinabove and disclosed 15 more in detail in the specifications which follow.

Another object is to providel improved remote control means for stopping, starting and adjusting the various features of the apparatus.

' Another object is to provide an improved ther- 20 mostatically controlled means for adjusting the generator fires in accordance with temperature changes at a remote location.

Another object is to provide an. improved normally constantly burning pilot burner, with co- 25 operating thermostatic means for cutting off the fuel supply toall burners when this pilot burner is extinguished.

Another object is to provide a secondary pilot or control burner adapted to actuate means for 30 controlling the fuel supply to the main burner in accordance with temperature changes at a. point remote from the generator, and also in accordance with variations in the draft of the combustion air produced by the exhausting mech- 35 amsm.

Another object is to provide an improved blowback safety mechanism adapted to cut off the supply of fuel in case of a back-lire from the generator. Y 40 Other objects and advantages of this invention will be more apparent from the following detailed description of certain approved forms of apparatus adapted for carrying out the principles of the invention. v

In the accompanying drawings:

Fig. 1 is a general diagrammatic elevation of the heating system. v

Fig. 2 is a central vertical section through the. generator. 50

Fig. 3 is a plan view of the burner and control valve assembly.

Fig. 4 is an end elevation looking from the right at the structure shown in Fig. 3.

Fig. 5 is a plan view, partially in section, of 65 the secondary or control pilot and the valve operated thereby.

Fig. 6 is a side elevation, partially in section, of the structure shown in Fig. 5.

Fig. 7 is a side elevation, partially in section, of the main pilot burner.

Fig. 8 is a detail section, taken substantially on the line 3-8 of Fig '1.

Fig. 9 is an end elevation of the control valve assembly, looking at the left at the assembly shown in Fig. 3.

Fig. 10 is a longitudinal horizontal section through the main burner.-

Fig. 11 is a front elevation, with the cover platek` removed, of the electrically operated valve and switch mechanism.

Fig. 12 is a horizontal section, taken substantially on the line I2-I2 of Fig. 11.

Fig. 13 is a vertical section, taken substantially on the line |3-I3 of Fig. 12.

Fig. 14 is a vertical section through one of the thermostatically controlled valves.

Fig. 15 is a partial elevation and partial vertical section showing one of the radiator inletvalves.

Fig., 16 is a diagrammatic assembly showing a wiring diagram and the fuel-feed connections, parts being shown in section.

Fig. 1'7 is a horizontal section showing a modifled form of burner assembly.

Fig. 18 is an elevation, partially in vertical section, showing the safety thermal cut-olf switch.

Fig. 19 is a wiring diagram showing a modified form of control assembly.

' Fig. 20 is a wiring diagram showing another modification of the control mechanism.

The main elements of theI apparatus are a'generator for the heating medium indicated at A, a burner assembly and control mechanism indicated generally at B, .a manually operated remote control and signal mechanism C, thermostatically operated temperature control devices indicated at D and D', a radiating system comprisingthe several radiators E, andthe exhausting mechanism indicated at F. The burner assembly com- -prises the main burner G, the primary pilot burner H, and the secondary or control pilot Kv (see Fig. 3).

Referring first more particularly to Figs. 1 and 2, the generator A may take a variety of forms, a preferred form of generator being here disclosed by way of example. An essential characteristic of this generator is that it is'entirely closed except for the inlets for water,'fuel and combustion air, and the outlets for the heating medium and excess water. None of these, except the inlet for combustion air, has any direct connection with the atmosphere within the building so that a reduced pressure may be maintained with- I in the generator and the escape of fluid therefrom is prevented. 'I'he generator may be made of metal or suitable refractory materials, or both, preferably comprising an outer metallic shell covered with suitable insulating material (not here shown) in order to prevent heat losses. A lower substantially closed metallic housing I rests upon and is sealed to a concrete supporting base 2 formed with the sump 3, from which .leads drain pipe 4 which may empty into the sewer connections indicated at 5. A side extension 6 of the lower casing I houses the burner and control valve mechanism, indicated generally at B. Suitably mounted in and supported by the metallic cover plate 1 of lower casing I is the main lower combustion chamber 8 formed of suitable refracwhich the fuel and flame from main burner G,

and the combustion air, enter the combustion chamber I2. Due to this tangential opening, the combustion fluids and flame take a spiral or spinning path ythrough the combustion chamber I2, whereby a very long flame and complete comy bustion may be attained almost entirely within the relatively small combustion chamber before the hot products of combustion pass out into the mixing chamber I4, thereabove.

The outer substantially cylindrical metallic shell I5 of the steam generator and mixing chamber is supported by the cover plate 1 or forms an upward extension of lower casing I. The dome or cover I6 of casing I5 leads up to a central outlet opening |1 with which communi cates the main outlet or supply pipe I8, through which the heating medium is conducted to the radiating system E. The inner metallic shell I9 is formed at its top with a'dome- 20 provided with a central opening 2| through the downwardly extending cylindrical overflow flange 22. This central opening 2| is also in vertical alignment with the outlet conduit I3 and serves as an outlet for the heating medium from the mixing chamber I4 within inner casing I9. The annular space 23 between inner and outer shells I! and I5 is normally lled with water up toj the level of overow opening 2|, through which excess water ows downwardly into chamber I4, as indicated by the ldrops 24. A shallow ash plate or pan 25 is supported by legs 26 from cover plate 1, the ash plate25 being positioned substantially centrally within the mixing chamber I4. A water-'heating pan or receptacle 21 is supported be" neath overflow opening 2| by the central post 23 extending upwardly from flash plate 25. 'I'he upwardly extending side walls of pan 21 are provided near their upper 'edges with a circumferentially extending series Vof restricted outlet openings or slots 29. The water falling atv 24 through overflow opening 2| will accumulate in heating pan 21 up to the level of outlet openings 29 through which the heated water, which has is mounted at its lower end on cover plate 1 and not already been vaporized, will overflow as indicated at 30, onto the flash pan 25. The purpose of the overilow openings 23 is to secure a better distribution of the overflow water in case heating pan 21 is not exactly level.

A water supply pipe 3| communicates with the annular Awater space 23, this pipe leading from the lower portion of return pipe 32 throughwhich condensate is returned to the generator. A supply pipe 33 leading from the outsidev water supply and provided with cut-off valve 34 also communicates with the water inlet pipe 3|. -A scalecollecting pocket and drain connection 35 may be provided at the lower end of water return pipe 32. At 36 is a drain plug whereby the annular climber 23 may be drained and flushed out, and

overflow onto ash pan 25, as already described. 7,5;

In operation the highly heated products of conbustion rising from combustion chamber I2 pass under and around the ash plate 25 so as to convert all or the greater portion of the lm of water thereon into steam. These products of combustion also contact with the water falling through or from ovcrow opening 2 I, as indicated at 24, and from heating pan 21, as indicated at 30, whereby additional steam is generated. The rising products of combustion will highly heat the water in pan 21, so that some steam will be generated from this body of water, and so that the water which drops onto the flash plate 25 will already be raised to a high temperature. The hot gases rising through mixing chamber I4 will heatrthe annular body of water in chamber 23 so that additional steam is generated from this water, all of the mixed gases consisting of steam and products of combustion passing out through the main supply pipe I8 to the radiating system. It will be noted that the mixing chamber I4 is entirely closed at its lower end except for the inlet opening for the flame and combustion air at I3 through combustion chamber I2, and the only outlet being through the supply main I8 through which the heating medium passes out. The entire generator will preferably be protected by an outer covering of insulating material (not here shown) so that the heat losses will be minimized, and practically all of the heat generated is carried out to the radiating system by the heating medium discharged through pipe I8.

Since practically all of the condensate from the radiating system is returned to the generator through pipes 32 and 3|, and since additional water is always being formed in the combustion process from the hydrogen in the gas and the oxygen in the air, there will ordinarily be a surplus of water supplied to the generator. Any excess of water that is not vaporized on flash pan 25 will overflow, as indicated at 39, and

then drain out through pipe 40, preferably provided at its lower end with water-seal 4I, thence flowing through drain pipe 4 to the sewer connection at 5.

The heating medium passes from supply main I8 through the respective risers 42 and inlet valves 43 into the several radiators E. While only three radiators have here been shown by way of example, it is to be understood that a greater number of radiators can be used. Each inlet valve 43 comprises the usual cut-orf valve operated by handle 44, and a metering plate 45 provided with a central orice 46 is interposed at some selected position in the conduit system, as here shown between the valve chamber and the passage 41 leading into the radiator E. The oriice 46 in plate 45 will be proportioned to meter the right proportion of heating medium to each radiator, depending upon the size. volume and condensing capacity of the radiator. It will be understood that when valve 43 is closed, practically no heating medium is admitted to the radiator. but when the valve is opened a restricted flow of heating medium is admitted to the radiator through the orilce plate 45. Discharge pipes 48 lead from the respective radiators E into the vertical return main 32, in the lower portion of which the condensate from the radiators accumulates and ows back through pipe 3| into the generator A.

At a, point somewhat above the water level in the generator A, a branch pipe 49 leads from return main 32 to the exhausting apparatus F. This keeping the humidity within the flue to a desired low value, thus preventing moisture accumulating in the flue and seeping through the wall with consequent damage to the interior wall decorations. This exhausting apparatus Ff'not onlyI draws out and expels the non-condensible gases from the radiating system, but serves to create a small suctionor sub-atmospheric pressure in the system which is increased by the vacuum created by condensation of steam in the radiators E. This sub-atmospheric pressure, which extends into the generator A, serves to draw in the combustion air at the burners and also prevents leakage of combustion gases from any part of the system, since leakage (if any occurs) will be of air into the system, due to the sub-atmospheric pressure existing therein.

l Referring now more particularly to Figs. 3 to 13 inclusive and 1G, the burner and control valve assembly will be described more in detail. The gaseous fuel ilowsinto supply pipe 55, in which is positioned the g'as regulator 56, which may be of the well known diaphragm-operated type or any other suitable type. At 51 is a main cut-olf valve automatically operated by the primary pilot burner H, as hereinafter described in detail. When Valve 51 is closed, the supply of fuel is cut off from all the burners. From the main cut-'01T valve 51 the gas ilows through pipe connection 58 to the electrically operated control valve 59, which is operated by the remote convtrol mechanism C (hereinafter described in detail) to completely cut off or to regulate the volume of the gas ow through pipe 60 to a second automatically operated cut-olf valve GI. This valve 6I is operated by a thermostatic coni trol mechanism responsive to the intensity of the ,i The gas ilows through nozzle 65 into the mixing chamber 66, the volume of the gas flow being controlled by the tapered regulating plug 61 carried by adjusting screw 68. Air is admitted to mixing chamber 66 through the annular opening 69 between the open rear end of mixing chamber 66 and the adjustable closure cap or head 10. The combustible mixture ows through tube 1I to the outlet member 'l2 of restricted diameter, in the tapering approach to which is a series of holes or openings 13 for the purpose of securing intimate mixing of the air and gas, keeping the name from blowing off the end and going out. The combustion .takes place or the llame forms beyond the end 14 of the burner. the flame being projected through tangential opening I3 into the combustion chamber I2, as already described.

Inasmuch as the number of radiators in use affects the rate of condensation and also the suction produced by the exhauster, it will be evident that the turning on or oft of radiators automati- 75 cally varies the quantity of heating medium produced in the generator as the result of varying the resistance to fluid flow into and through the system, which in turn varies the quantity of air owing through the burners and inlet opening I3.

' Returning now to the control valves,l the primary pilot burner H and main cut-off valve 51 will first be described, referring more particularly to Figs. 3, 4, '1, 8, and 9. The supporting tube 15 projects from the casing or housing 16. which extends upwardly from the housing of cut-off valve 51. The fuel supply tube or conduit 11 projects through tubular casing 15 and is provided at its outer end with the burner opening 19 where the pilot llame is formed which projects across the outlet end of the main burner G, so as to serve to ignite the main burner (see Fig. 4). Thel thermostatic operating member comprises a thermal tube 19 mounted at its inner end in casing 16 and projecting at its outer end into the path of the flame of the pilot burner, so that when the pilot burner is in operation, tube. 19 will be heated and will expand, thereby drawing out a rod 90 which is slidably mounted within the tube 19 and secured thereto at its outer end 9 I At the inner end of rod 90 is a knife edge thrust member 92 bearing against an intermediate portion of a lever 99 fulcrumed at its upper end on a knife-edge 94 carried by a fixed bracket member 95. The

lower forked end 96 of lever 93 bears against one end of a compression spring 91 mounted. on the outer end portion of the valve stem 99. The valve 51 opens when stem 99 is moved toward the right and is closed when stem 99 is moved toward the left. The spring 99 on the inner portion of stem 99 tends to open the valve, but when tube 19 is closed and lever 93 is moved toward the left (as shown in the drawings), the consequent compression of spring 91 will'cause this spring to overcome the force of spring 89 and close the valve 51. When the pilot flame is burning, the

tube 19 will be heated and will expand so as to draw rod 90 to the right (Fig. 1) thus permitting lever 93 to swing toward the right and relieving the compression of. spring 81, thus permitting spring 99 to open the valve 51. The fuel supply pipe 11 for the pilot burner communicates with a passage 90 formed in casing 15, into which is connected the supply pipe 9| leading from the three-way fitting 92. Supply pipe 99 leads to this fitting 92 from the inlet side of the housing of electrically-operated valve. 59 (see Fig. 13) so that as long as main cut-off valve 51 is open, fuel gas will flow to the pilot burner Hthrough pipe 59, valve housing 59, pipe 93, fitting 92, pipe 9|,

i passage 90, and supply pipe 11. However, when main cut-off valve 51 is closed, this fuel supply connection for the pilot burner H will be cut off, so that an auxiliary connection must be provided for supplying fuel to this pilot burner when it is f'lrst lighted and until the thermostatic tube 19 has been expanded to permit the opening of cutoil valve 51. For this purpose, an auxiliary supply pipe 94 leads from the main gas supply pipe 55 at the inlet side of cut-off valve 51 into the threeway fitting 92. A normally closed push-button valve 95 is positioned in this auxiliary supply pipe 94. When the apparatus is first put into operation, the operator will push down the button valve 95, thus permitting a flow` of fuel to the pilot burner from pipe 55, through pipe 94, fitting 92, pipe 9|, passage 90 and pipe 11 to the burner .opening 19 where the gas is ignited by any suitable means. The operator must hold the push pilot button valve 95 open until the flame at 1l has heated up thermostatic tube 19 sumciently to permit the main cut-off valve 51 to open. As soon as valve 51 has opened, gas will flow through the pipe connections first described to supply the pilot burner and the push button valve 95 may be permitted to return to its normally closed position. There will now be a continuous flow of fuel to the pilot burner Has long as valve 51 remains open, and valve 51 will remain open as long as the pilot burner is in operation. Therefore, this pilot burner will normally burn constantly, but if for any reason it should be extinguished, the main cut-oil valve 51 will automatically close and the supply of fuel will be entirely cut oiI to all of the burners, including the main burner G, the primary pilot H and the auxiliary K, hereinafter described.

The electrically operated remote controlv valve system C will now be described, referring more particularlyr to Figs. 3, 9, 11, 12, 13 and 16.

The gas flows through pipe or conduit 50 into the main gas chamber 96 in valve housing 59. A cylindrical bushing 91 is fixed in this housing, and is formed with a main gas passage 99 communicating with chamber 96, also with a smaller passage 99 and with a still more restricted passage |00, the three openings 99, '99 and |00 being positioned at 90 from one another about the circumference of bushing 91, the fourth side of and is provided with an opening |06 adapted-to register selectively with any one of the openings 99, 99 or ||I0 in the bushing or vto be presented against the closed side |0| of the bushing, in which latter position the flow of gas through the valve will-be completely cut o'. The valve member is closed at one end by a head |01 which also closes this end of the bushing 91, the opposite ends of the bushing 91 and valve member |05 being open to permit the gas to flow dut through the housing extension |09 and the conduit 50 fitted therein. It will now Abe vapparent that this valve is to be adjusted successively 'to' Fig. 13. In the position shown in the drawings,

the valve is completely closed. When rotated through 90 so that the opening |06 in-the rotatable valve member |05 registers with the larger opening 99 in bushing 91, a substantially unrestricted flow of gas through the valve isV permitted. Another adjustment of 90 brings opening |05 into register with the smaller opening 99 to permit a more restricted flow of -gas through the valve. When moved to the third position a still smaller flow of gas through restricted opening |00 is permitted. In the nal or fourth position. as shown in the drawings', the valve is closed. In order to automaticallyaccomplish these rotary adjustments of the valve, four :pins |09 project from the head |01 into the enclosing housing |09, the pins being spaced at 90 from one another about the axis of rotation of the valve membe A lever I0 intermediately fulcrumed at I l witharmature I |3 of a solenoid or electro-magnet I I4. A pawl I |5` having one hooked end' I |6 adapted to engage any one of the pins |08, is pivotally mounted at its otherend |I1 on the upper end of intermediately pivoted lever 0. A coiled contractile spring II8 `is anchored at one end ||9 in the housing |09 and is secured at its other end to an upwardly projecting lug |20 formed on pawl ||5 near its pivoted end |I1. This spring IIB tends to return the parts to the position shown in Fig. l1 when solenoid II4 is de-energized, and also tends to swing the hooked end of pawl |I5 downwardly so as tion to engage one of the pins |08.

Referring now for the moment to the wiring diagram shown in Fig. 16, 2| and |22 indicate electric mains through which current is supplied to the transformer |23. Current flows from transformer |23 through wires |24, I25and |26 to one side of the push button |21 of the control mechanism.C, which may be positioned at any convenient position Within the building to be heated. From push button' 21 the circuitv is completed through wire |28, coil of vsolenoid II4, and wire |29 back to the transformer |23. Whenever push button |21 is closed, the magnet or f solenoid ||4 will be energized, thus drawing in coil |I3 and through lever ||0, moving pawl ||5 to the right (Fig. 11) thereby turning the rotary assembly of the valve through an arc of i 90. -When the push button |21 is released, the magnet I|4 will be de-energized and spring ||8 will return the parts to the position shown in Fig. 11, the beveled end II6 of pawl ||5 sliding up over the next succeeding pin |08 until the hooked end of the pawlcan be moved down into engagement with this pin through thev effort/,of spring IIB exerted on lug |20 of the pawl. "Ihe next time push button |21 is closed, the same cycle of events will be repeated and the rotary assembly will be shifted in the same direction through another arc of 90. i I

A pair of signal lights, which may conveniently comprise a lower red light |30 and an upper white light |3I, are preferably mounted adjacent the push button |21 as a part of the control mechanism C, as indicated in Fig. 1. A spindle |32 projects outwardly from rotary head |01, and a spring contact member |33 is constantly in engagement with this spindle, this spring 'contact being connected through Wire |34 with one side of transformer |23. A pair of contact pins |35 and |36 mounted in spindle |32 and spaced 180 apart are adapted to alternatively contact with the spring contact member I 31 which is connected through wire |38 with one terminal of the signal light |3|,-the other terminal of this light being connected through wiresv I 39 and |24 with one side of transformer |23. A similar pair of contact pins |40 and 4| spaced 90 apart, are adapted to contact with spring contact member |42 connected through wire |43 with one terminal of signal light |30, kthe other side of this light being connected through wires |44, I 25 and 24 with the transformer |23. A disc |45 of insulating material is iixedly mounted on spindle |32, this `disc having one at side |46 which is presented upwardly, as shownin Fig. 11when the valve is in closed position. A movable contact member |41 will be heldin engagement with a fixed contact member I 48 as long as the spring arm |49 which carries the movable contact |41 is held up by the cylindrical periphery of the Idisc |45 on which it rests. Whenever the flat face |46 of disc |45 is uppermost, this spring arm |49 will to always bein posi- -burner is being |22. It will now be apparent that as long as the contacts |41 and |48 are held in engagement, the exhauster motor 5I will operate, but when the contact between members |41 and |48 is broken, the motor 5| will be de-energized and the exhausterfan 50 will cease to operate.

The rotary assembly comprising thevalve sleeve |05 andthe spindle |32 and the contact members carried thereby rotates intermittently in a clockwise direction, as seen in Figs. 11 and 13. In the first or "0E position, with all parts at rest or not functioning, this rotary assembly will be positioned as shown in the drawings. At this time the valve 59 will' be closed and no gas will flow to the burners since closedv portions of the With the parts in the positions just described,

if push button |21is closed, the solenoid 4 will be energized, acting through the lever and pawl mechanism, already described, to swing the rotary assembly through an arc of 90. The valve Will now be opened to its' maximum by bringing the port '|06 in the valve sleeve |05 into register with the main gas passage 98. The cylindrical surface of disc |45 will be moved under the spring arm |49 so as to close the contacts |41 and |48,

thus causing-the exhausting mechanism F to operate. The two contact fingers |35 and |40 will be moved into engagement with the spring contacts |31 and |42, thereby causing both signal lamps. |30 and 3| to belighted. The two lights burning simultaneously indicate that the main supplied with a maximum ow of 83S.

If it is desired to restrict the ow .of gasto the main burner D and thus cut down the heat output, button |21 will be closed a second time, thereby moving the rotary parts through a second arc of 90. This will bring the port |06 into registry with the port 99, so that only a reduced ilow of gas to the burner is permitted through the valve. The contact lingers |35 and |40 will be moved out of `engagement with spring fingers |31 and 42, but the single contact linger |4| will be moved into engagement with spring contact |42 so as to continue the illumination of the lower light |30. The upper light I3I will not be illuminated at this time, and the single signal light |30 will indicate that the intermediate or reduced heat is on. The exhauster will continue to function as before (the cylindrical surface of disc |45 still remains in engagement with spring arm |49) A third operation of push button |21 will move the Valve through a further arc of 90, thus bringing port |06 into registry with the restricted opening |00 so that only a very limited flow of gas is permitted to the main burner. However, the exhauster will continue to operate At thisv time, contact nger |4| will be moved out of engagement with spring contact |42, but the finger |38 will now be moved into engagement with spring contact |31. `This will cause the illumination of the upper signal light |3| only, thereby indicating that the burner is now adiusted for the most restricted heat production.

A fourth operation of 'push button |21 will complete the cycle and return all of the parts to the position shown in the drawings. In this position both signal lights are out, the valve is completely closed, and the exhauster F is not in operation.

From valve 58 the gas flows through pipe 88 -to the cut-off valve 8|., which is under the control of the secondary pilot or control burner K (see particularly Figs. 3, 4, 5, 6 and 16). The housing of valve 8| is formed with an internal web |53 provided with valve passage |54, at the inlet endl of which is valve seat |55, against which seat the movable valve member |58 is carried by balljoint |51 at the inner end of valve stem |58.

Valve stem |58 projects through a sealing means indicated generally at |58, the outer end of the stem being positioned in a housing, indicated at |88. The housing |88 contains a quick-acting mechanism for moving the valve member |58 quickly and positively from opened to closed positions or vice versa. This mechanism comprises a lever |8| having a knife edge |82 at'its lower end fulcrumed against a fixed abutment in the housing |88, and having a knife edge |83'at its upper end engaging a plate |84 at the' lower end of compression spring |85, which engages at its upper end a plate |88 fulcrumed against the knife-edge |81. It will now be apparent that when lever v|8| is swung to either side of a vertical or `dead-center position, the expansion of spring |85 will snap the lever quickly to its limit of movement at that side of the vertical. A pair of knife-edges |88 and |88 onthe upper arm of lever |8| alternatively engage adjustable washers |18 and |'1l mounted on valve stem |58, so that the snap action movement of lever |8| to one side or the other of the vertical will move the valve stem |58 and 'consequently move valve member |58 to open or closed positions. An operating rod |12 is pivotally connected at one end, |13, to lever |8|, this rod projecting out through a tubular housing |14y attached to the housing |88. -At the outer end of tubular housing |14 is mounted the flue housing |15 which is positioned substantially horizontally and is formed with one closed end |18 and an elbow |11 at the other end, having an upper opening |18 positioned adjacent the outlet of main burner G (see Fig. 4). The flue housing is provided with small air or draft openings, indicated at |18 and |88, so that the suction of the combustion yair being drawn into the generator combustion chamber at I3, will cause a draft or flow of air into flue housing |15 through openings 18 and |88 and out through the open end |18. The outer end of operating rod |12 is pivotally connected within the flue housing |15. The burner |84 is .mounted lin the inner wall of housing |15 and is supplied with gaseous fuel through tube |85, as hereinafter described.

when the exhausting mechanism F is not operating, the draft through housing |15 will be so small that the ame -|85 of. burner |84 will burn lazily, as indicated in solid lines in Fig. 5, and will have no substantial heating effect on thermostatic element |82, at least not enough to move the valve member, which will remain closed. as shown in the drawings. However, as soon as the exhausting mechanism is started into operation, the draft through flue |15 will be increased so that the burner flame will be intensified, as indicated in dotted lines at |88, thus heating the bi-metallic thermostatic bar |82, so that it will bend out, substantially as indicated in dotted lines, and thus. move lever |8| past its deadcenter position so that the snap action will open the valve 8|. When the exhausting mechanism ceases to operate, the flame of burner |84 will return to its lazy position and the consequent cooling of thermostatic bar |82 will cause valve 8| to be automatically closed. It will be apparent that when valve 8| is closed, the flow of gas to main burner G through pipe 62 will be cut oi. It will lbe apparent that the action of this thermostatic valve operating mechanism will not be instantaneous, and a slight time interval will elapse after the exhausting mechanism has been turned on, before the valve 8| is open to establish a g'as ow through the mainburner. This affords an opportunity for an air current to be established in the proper direction and prevents the possibility of. back-drafts which might occur before the fan operation had been fully established.

A gas supply conduit |81 is connected through fitting |88 with an extension |88 of valve housing 8| at the inlet side of' the valve so that the ow of gas through conduit |81 will be uninterrupted, regardless of the open cr closed position of valve member |58. This conduit |81 leads to the thermostatic control valve D (see Figs. 1, 14 and 16), and the conduit |85 leads from this control valve to the burner |84, so that as long as control valve D is open, a continuous iiow of gas will be established to the auxiliary pilot burner K. In the example now being described, the thermostatic valve D is positioned in o r adjacent to the conduit 48, through which the exhaust gases are drawn into the suction fan 58, so that this valve will be responsive to the temperature of these exhaust gases. A type Iof valve well suited for this purpose is shown in Figs. 14 and 16. Within the casing |88 is mounted the valve housing |8|,in which is valve seat |82 with which cooperates the movable valve member |83. The spring |84 tends to open this valve, and the valve is closed by an inward pressure on plug |85, which projects through the sealing diaphragm |88. The

inlet and outlet conduits |81 and |85 connect connected by means of nuts 284 and 285, with an intermediate portion of pivoted carrier |88.

The mechanism may be adjusted by moving the at |8| to the free end of a bi-metallic thermostatic bar |82 which is fixed at its other end |83 nuts 284 and 285 on the threaded portion of link 28 l'. A regulating lever 288, positioned outside of casing |88, is fixed on ashaft 281 and its upper at D' the thermostatic bar |91 carried thereby. When thermostatic bar |91 is heated, it will swing toward the right (Fig.r 14) so as to close the valve, and the temperature at which this closure will 'take place is determined by the adjustment of regulating lever G.

It will now be understood that when the exhaust gases drawn into fan 50 are too hot, thus indicating that excess heat is being furnished to the radiating system, the valve D rwill `automatically close, thus cutting olf the supply of fuel to auxiliary pilot burner K. 'I'he thermostatic bar |82 will then cool or contract and cause valve 6| to be automatically closed, thus cutting oil.' ,the supply of fuel to the main burner G. When the exhaust gases commence to come through cool from the radiating system, the

valve D will be automatically opened, thus reestablishing the supply of fuel to burner |84, The vflame will be re-ignited at the outlet |18 from the constantly burning main pilot H, and as'soon as pilot name |86 has heated up the thermostatic bar |82, the valve I I will again be opened to re-establish the supply of fuel to main burner G, which will also be ignited from the constantly burning pilot H.

Instead of positioning the valve D so as to be responsive to the temperature of the exhaust gases, the valve could be positioned as indicated (Fig. 1) so as to respond to the-temperature established at any desired point within the building. When the desired temperature had been reached, the valve D' will cut off the supply of fuelto pilot burner K.'which will in turn cause Ythesupply of fuel to main burner G to be cut off,

so that the generation of heating medium will be temporarily discontinued or diminished.y Alternatively, both valves D and D can be arranged in series in the supply conduit for burner K, or a plurality of such thermostatic valves can be so used, any one of which will serve to cut off the supply of fuel to the auxiliary pilot when a certain maximum temperature has been reached at any of the locations where these valves are positioned.

In starting this heating apparatus originally, or after a period of dis-use, the push button valve 95 must be depressed and the primary pilot H ignited at 18. The push-button 95 must be held depressedvuntil the valve 51 has been automatically opened by the thermostatic mechannism 11, after which the push button valve may be released and the primary pilot will continue to burn. `If the push button control switch |21 is now pressed once, a maximum flow of gas will be established through valve 59 and the exhausting mechanism F will be started into operation. Gas Will now flow to the secondary pilot K, which will be ignited from the primary pilot H, and, since the fan is in operation, the fiame of the secondary pilot will burn with suiiicient intensity to cause the valve 6I to be automatically opened after a short time interval, thus establishing a ow of fuel to the main burner G which will in turn be ignited from the primary pilot H. -Heating medium will now be generated and will flow into the radiators E, the non-condensable gases being drawn out by exhausting mechanism F and expelled intofue 53. If these gases come through hot, thus indicating that excess valve D Will autodescribed.

is desirable, the push button, I21`may be actuated a, second time, or even a third time, to successive-` ly restrict the flow of gas to the main burner. A fourth actuation of push button |21 will en'- tirely close valve 59 and stop the exhausting mechanism F. The burners H and G will continue to burn until the conduit beyond valve 59 has been cleared of gas, and valve 6I will automatically close, after. a short time interval.

If, for any reason, the exhausting mechanism should cease to operate at any time, the draft through flue housing I 15 Will a't once be cut down sor that the auxiliary pilot K and its cooperating thermostatic mechanism will cause valve 6I to be closed and main burner G will cease to function. The auxiliary pilot K will, however, continue to burn lazily and will cause valve 6I to be automatically opened when the fan is again started in operation. The main pilot H will normally burn constantly, even though all of the other mechanism has been rendered inoperative. However, if this primary pilot should be extinguished by a back-fire or for any other reason, the cooperating thermostatic mechanism will cause cut-off valve 51 vto be closed, thus shutting oli' the supply of fuel to cluding` the primary pilot H.

Emergency pressure relief valves and observation ports may be installed in each of the supply and return sides of the system. In Fig. 2, the valve casing 2|I has a lower flange 2I2 for attachment to the top I6 of the generator, and is internally threaded in its upper end to receive the supply main I8. The casing 2|| is formed internally so that water will drip downwardout of the casing. The ap or closure 2| 3 is hinged at its upper edge 2M, and rests upon the inclined seat 2I5 so that it will be held shut by gravity, also by the outer atmospheric pressure when the system is normally operating under a partial vacuum. 'I'he flap 2I3 should be thick enough not to Warp under the temperatures to which it is subjected, and may, if desired,.be made of brass or other non-corrosive metal to prevent rusting shut. If, for any reason, super-atmospheric pressures should be developed in the system, this ap valve will blow open and relieve pressure. The iiap 2 I3 may also be raised at any time for observation purposes.

A similar iiap valve 2I6 is positioned in the return main, for example above the connection be provided with a vitreous coating or other form of rust-proofing. This corrosive action is largely caused by excess of air in the system, and since this improved system operates under a partial vacuum, excess air is practically eliminated and corrosion is minimized.

Referring now to Figs. 17, 18 and 19, certain modications of the heating apparatus will be much the same as that already described, except that the secondary control pilot K and cut-off valve 6I are omitted, and a solenoid operated cutofi valve 2I8, of any standard type is inserted in the gas line between the first cut-Off valve 51 In Fig. 17, the assembly shown is F 225 is yieldably carried at the bottom of a plunger 221, which normally tends to be lifted by spring means so as to break the circuit by lifting bridge plate 225 from the fixed contacts 22| and 222. The switch is closed by depressing the plunger at 228', whereupon the spring pawl 229 will engage the normally non-rotating ratchet wheel 230 to lock the plunger in depressed position with the switch closed. -The ratchet wheel 230 is xed by means of a fusible solder of low melting point, indicated at 23|, on the inner end of a copper rod 232, the outer end of which extends adjacent the outlet end of main burner G. In case the burners back-fire for any reason, or thefiames burn back at the outlet orifice of the main burner, due to poor draft conditions, the copper rod or tube 232 will become heated so as to melt the fusible metal 23| and permit ratchet 230 to rotate so-that the locking mechanism will no longer be effective and plunger 221 will be raised by its spring so as to break the circuit. The solenoid of valve 2|8 will vthus be de-energized so that it will automatically close and cut off the fuel supply to the burners. The Wiring diagram shown in Fig. 19 shows the connection for the element just described, with the addition of a thermostatically operated circuit breaker 233, which may be located at any desired'point in the system. Parts of the wiring connection not specifically referred to may be the same as in the wiring diagram shown in Fig. 16, and already described. The solenoid operated valve 2IB is connected by wires 234 and 235 in parallel with the operating circuit of exhauster motor 5|. The thermostatic circuit breaker, indicated generally at 233, (which may be of any suitable type) is connected in one of the wires such as |5| of the motor-operating circuit. In case an abnormal heat i reached at any point where circuit breaker 233 may be located, the thermostatic mechanism will operate to break the circuit, whereupon motor 5| and solenoid 2|8 will be de-energized so that the exhauster mechanism will cease operating and the solenoid valve 2I3 will automatically 'cut off the flow of fuel to the burners. The safety switch 2|9 is located in one of the main circuit wires, such as |22, so that if this switch is opened by a blowback from the generator, all be broken and the valve 2 I8 will be automatically closed.

In the modification shown by the wiring diagram of Fig. 20, a motorized gas valve 236 of standard type and controlled by the thermostat 231, located at any desired position in the building,` serves to cut the fuel supply on and off at certain predetermined temperatures. This motorized gas valve includes a safety cut-out valve which will close when the operating circuits are broken. The valve 235 therefore takes the place of the push button control mechanism first described, as well as the safety solenoid valve 2|8. As indicated, the safety thermostatically operated circut breakers 2|9 and 233 are included in the operating circuit for motor 5| and motorized valve 236, so that the exhausting mechanism will be stopped and the fuel supply cut off whenever either of these thermostatic devices are subjectedA 7 to abnormal temperatures. It will be .apparent of the circuits will that various other combinations of the several safety features hereinabove described could be formed without departing from the principles of this invention.

The specific generator herein disclosed and the specific process of generating the heating medium are not claimed herein but are disclosed and claimed in our co-pending application Serial No. 759,966, filed December 31, 1934.

We claim:

1. The method of heating consisting in-burning fuel in the presence of `water in a closed combustion space to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partialvacuum in the condensing and combustion spaces, causing circulation of the heating medium, and producing a suction for drawing fuel and combustion air into the combustion space, returning the condensate to the combustion space, and automatically controlling the combustion by respectively increasing or decreasing the supply of fuel in response to an increase or decrease in the suction produced at the inlet lto the combustion space.

2. The method of heating consisting in burning fuel in the presence of water in a closed combustion space to produce a partially condensable4 heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space finto which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing and combustion spaces, causing circulation of the heating medium and producing a suction for drawing fuel and com` bustion air into the combustion space, returning the condensate to the combustion space, maintaining a main combustion iiame and an auxiliary pilot flame at the inlet to the combustion space, increasing or decreasing the intensity of the pilot flame in accordance with corresponding varia'- tions in the suction produced at the inlet, and

increasing or decreasing the supply of fuel to the main flame in response to an increase or decrease respectively in the intensity of lthe pilot iiarne. i

3. The method of heating consisting in burning fuel inthe presence of water in a closed combustion space to produces, partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing spaceinto which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuurn in the condensing and'combustion spaces.'

causing circulation of the heating medium and producing a suction for drawing fuel and combustion air into the combustion space, returning the condensate to the combustion space, maintaining a main combustion name and an auxiliary pilot flame at the inlet to the combustion space, vincreasing or decreasing the intensity of the pilot` arne in accordance with corresponding variations in the suction produced at the inlet and alsoy in response to a decrease or increase respectively in the temperature of the gases exhausted from the condensing space, and increasing or decreasing the supply of fuelto the main flame in response to an increase or decrease respectively in the intensity of the pilot flame.

4. The method of heating'consisting in burning fuel in the presence of Water in a closed combustion space to produce a partially condensable heating medium consisting of`products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled nonfcondensable gases from the condensing space and thereby maintaining a. partial Vacuum in the condensing and combustion spaces, causing circulation of the heating medium and producing a suctionl for drawing fuel and cornbustion air into the combustion space, returning the condensate to the combustion space, maintaining a main combustion flame and an auxiliary pilot iiame at the inlet to the combustion space, increasing or decreasing the intensity of the pilot ame in accordance with corresponding variations in the suction produced at the inlet, and also in accordance with a predetermined increase or decrease in the quantity of heat given out from the condensing space, and increasing ordecreasing the supply of fuel to the main flame in response to an increase or decrease respectively in the intensity of the pilot flame.

5. The method of heating consisting in burning fuel in the presence of water in a closed combustion space `to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space into -which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial Vacuum in the condensing and combustion spaces, causing circulation of the heating medium, and producing a suction for drawing fuel and combustion air into the combustion space, returning the condensate to the combustion space, and intermittently stopping or starting the combustion in response to a decrease or increase respectively in the suction produced at the inlet to the combustion space.

6. The method of heating consisting in burning fuel in the presence of water in a closedy oombustion space to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing` and combustion spaces, causing circulation of the heating medium, and producing a suction for drawing fueland combustion air into the combustion space, returning the condensate to the combustion space, there being a main combustion flame and an auxiliary pilot flame utilized at the inlet to the combustion space, increasing or decreasing the intensity of the pilot flame in response to an increase or decrease respectively of the suction produced at the inlet to the combustion space, and stopping the supply of fuel to the main flame by a decrease fin the intensity of the pilot name and renewing the supply of fuel to the main flame by an increase in the intensity of the pilot flame.

7. 'I'he method of heating consisting in burning fuel in the presence of water in a closed combustion vspace to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled non-condensablegases from the condensing space and thereby maintaining a partial vacuum in the condensing and combustion spaces, causing circulation of the heating medium, and producing a suction for drawing fuel and combustion air into the combustion space, returning the condensate to the combustion space, there being a main combustion fiame, a constantly burning pilot flame and an auxiliary pilot flame utilized at the inlet to the combustion space, stopping or renewing the supply of fuel to the auxiliary pilot fiame in response to a predetermined increase or decrease in the temperature of the exhausted gases, and stopping or renewing the supply of fuel to the main flame in response to the extinguishing or re ighting of the auxiliary pilot flame.

8. 'I'he method of heating consisting in burning fuel in the presence of water in a closed combustion space to produce a partially condensable heating medium consisting of-products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing and combustion spaces, causing circulation of the heating medium, and producing a suction for drawing fuel and combustionv air into the combustion' space, returning the condensate to the combustion space, there being a main combustion flame, a constantly burning pilot flame and an auxiliary pilot flame utilized at the inlet to the combustion space, stopping or renewing the supply of fuel to the auxiliary pilot flame in response to a predetermined increase or decrease in the quantity of heat given out from the condensing space, and stopping or renewing the supply of fuel to the main flame in response to the extinguishing or relighting of the auxiliary pilot name.

9. The method of heating consisting in burning fuel in the presence of water in a clo'sedccmbustion space to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space being connected with a condensing space into which the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing and combustion spaces, causing circulationof the heating medium, and producing a suction for drawing fuel and combustion air into the combustion space,` returning the condensate to the combustion space, there increasing or decreasing the intensity of the 50 auxiliary pilot flame in response to an increase or decrease of the suction produced at the inlet to the combustion space, stopping or renewing the supply of fuel to the auxiliary pilot flame in response to a predetermined increase or decrease 65 in the quantity of heat given out from the condensing space, and stopping or renewing the supply of fuel to the main flame in response to a decrease or increase in the intensity of the auxiliary pilot flame.

0 l0. The method of heating consisting in burn- 7 ing fuel in the presence of waterv in a closed combustion space to produce a partially condensable heating medium consisting of products of combustion and steam, the combustion space 75 being connected with a condensing space into which .the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing and commis--V intensity of the auxiliary pilot flame in respo to an increase or decrease of the suction produced at the inlet to the combustion space, stopping or renewing the supply of fuel to the auxiliary pilot flame in response to a predetermined increase or decrease in the temperature of the exhausted gases, and stopping or renewing the supply o! fuel to the main flame in response to a decrease or increase in the intensity ot-the auxiliary pilot flame.

CLAYTON A. DUNHAM.

AUBRA R. DUNHAM.

CERTIFICATE OF CORRECTION.

Patent No. 2,047,015.

July v, 195e.

`CLMETON A. DUNHAM, ET AL.

It ie hereby certified that error appears in the printed specification of `the above numbered patent requiring correction as fellows: Page l, second column, line 37, beginning with the word "Another" strike out all to and including, the word and period "generatoz". in line 40; and that the said Letters Patent should be read with this correction therein that the same may conform 'to the record o1" the case in the Patent Office.

Signed and sealed this 6th day of October, A. D. 1936.

(Seal) Henr Van Are Acting Comml'ssioner glfatents.

being connected with a condensing space into which .the heating medium is introduced, exhausting the cooled non-condensable gases from the condensing space and thereby maintaining a partial vacuum in the condensing and commis--V intensity of the auxiliary pilot flame in respo to an increase or decrease of the suction produced at the inlet to the combustion space, stopping or renewing the supply of fuel to the auxiliary pilot flame in response to a predetermined increase or decrease in the temperature of the exhausted gases, and stopping or renewing the supply o! fuel to the main flame in response to a decrease or increase in the intensity ot-the auxiliary pilot flame.

CLAYTON A. DUNHAM.

AUBRA R. DUNHAM.

CERTIFICATE OF CORRECTION.

Patent No. 2,047,015.

July v, 195e.

`CLMETON A. DUNHAM, ET AL.

It ie hereby certified that error appears in the printed specification of `the above numbered patent requiring correction as fellows: Page l, second column, line 37, beginning with the word "Another" strike out all to and including, the word and period "generatoz". in line 40; and that the said Letters Patent should be read with this correction therein that the same may conform 'to the record o1" the case in the Patent Office.

Signed and sealed this 6th day of October, A. D. 1936.

(Seal) Henr Van Are Acting Comml'ssioner glfatents. 

